JPS62263630A - Basket for wafer - Google Patents

Abstract

PURPOSE:To form a uniform film by mounting a vane for introducing a reaction gas and a vent hole to a top plate. CONSTITUTION:Wafers 2 are fitted to a wafer basket 1 at serval steps at regular intervals, and vanes 7 and vent holes 8 are formed to the upper disk of the wafer basket 1. The cross section of the vane 7 takes an S shape as a pinwheel, and a reaction gas 6 introduced from the upper section of a reaction pipe flows into a lower section along the vanes 7. Nonuniformity is not generated in a gas atmosphere in the upper section by the revolution of the wafer basket 1. Accordingly, the gas atmosphere having no nonuniformity can be obtained, thus forming equal films even on the wafers, films thereon have been uneven in a conventional method, in the upper section of the wafer basket.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a wafer basket, particularly a vertical structure diffusion furnace, a C
Concerning wafer pass care in VD equipment, etc.

BACKGROUND OF THE INVENTION As wafers become larger in diameter, vertical diffusion furnaces and CVD apparatuses have recently been attracting attention due to their thermal uniformity and dust reduction. That is, in contrast to the conventional horizontal apparatus in which the reaction tubes are arranged horizontally, this is an apparatus in which the reaction tubes are erected vertically. When such an apparatus is used, the wafers are placed horizontally in a wafer basket in several stacks at regular intervals. The situation is shown in Figure 3. The wafer basket 1 consists of four pillars 3 for holding wafers 2 and two upper and lower discs 4. Each of the disks 4 is a parallel flat plate and is provided with a rotating shaft for rotating the wafer basket. Furthermore, a hole 5 is provided in the center of the upper disk for temperature measurement with a pyroscope. Since the apparatus has a vertical structure, gas flows vertically within the reaction tube. Therefore, when using a conventional wafer basket, the reaction gas 6
The flow is obstructed by the upper disk 4, and most of it ends up around the outer periphery of the wafer.

Problems to be Solved by the Invention If the reaction gas 6 flows around the wafer as described above, even in a high vacuum state, the several wafers located at the top of the wafer basket will experience uneven gas flow. occurs, making it impossible to obtain uniformity of the film. Further, it is not appropriate to make the pyroscope hole 5 described above unnecessarily large because there is a risk that it will not be possible to maintain a parallel flat plate or that the axis of rotation will be misaligned due to high temperature heating.

Means for Solving the Problems In order to solve these problems, a structure is adopted in which the upper disk part is provided with, for example, a windmill-shaped spring, and ventilation holes are provided to improve ventilation of the reaction gas.

Function: According to the basket of the present invention, an even gas atmosphere can be obtained and a uniform film can be formed.

Embodiment An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a three-dimensional view of the wafer basket of the present invention viewed obliquely from above. Wafers 2 are placed in several stages in a wafer basket 1 at regular intervals.

The upper disk of the wafer basket is equipped with a spring 7 and a vent 8. The spring 7 has an S-shaped cross section, for example like a windmill. The reaction gas 6 introduced from the upper part of the reaction tube flows downward along the spring 7. Furthermore, due to the rotation of the wafer basket 1, there is no unevenness in the gas atmosphere above.

Effects of the Invention According to the wafer basket of the present invention, it is possible to obtain an even gas atmosphere as described above, so that a uniform film can be formed even on the wafers at the top of the wafer basket, where the film was non-uniform in the conventional method. be able to.

[Brief explanation of drawings]

FIG. 1 is a three-dimensional perspective view of a wafer basket according to an embodiment of the present invention, FIGS. 2A and B are a top view and front view of the same wafer basket, and FIGS. 3A and B are a top view and front view of a conventional wafer basket. It is a diagram. 1...Wafer basket, 2...Wafer, 6...Reaction gas, 7...Spring, 8
······vent. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2

Claims (1)

[Claims] A wafer basket used in a heat treatment furnace having a vertical structure, characterized in that the top plate is equipped with a spring and a vent for guiding a reaction gas.